Milecastle 68

Milecastle 68 (Boomby Gill) is a conjectured milecastle of the Roman Hadrian's Wall. The site of the milecastle (adjacent to Boomby Gill) has been calculated from measurement to known milecastle sites, but no remains providing proof of its existence have been identified.

Each milecastle on Hadrian's Wall had two associated turret structures. These turrets were positioned approximately one-third and two-thirds of a Roman mile to the west of the Milecastle, and would probably have been manned by part of the milecastle's garrison. The turrets associated with Milecastle 68 are known as Turret 68A (grid reference NY369575) and Turret 68B (grid reference NY368579), though no evidence of either has been identified.